Question: when did aleksey konstantinovich tolstoy marry sofia andreevna bachmeteva?
Paraphrase: When were Aleksey Konstantinovich Tolstoy and Sofia andreevna bachmeteva married?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q212575 p:P26 ?s . ?s ps:P26 wd:Q4079844 . ?s pq:P580 ?value}